The invention relates to a tube mill having a rotatably mounted milling tube with a grinding stock input end and a ground stock delivery end that is housed by a drop-delivery housing for delivering the ground stock and the mill gas.
Tube mills serve for crushing, or respectively, grinding, stock, which is usually transported in the rotary milling tube from the grinding stock input end to the ground stock delivery end using a mill air, or respectively, a drying gas, and is usually milled with the aid of grinding elements such as steel balls located in the mill tube, for which reason one speaks of air-swept mills, ball mills, and so on. It is known (EP-B-0184326) to arrange a delivery cone at the ground stock delivery end of a tube mill, which comprises openings that are distributed about the perimeter for delivering the ground stock and the mill gas. There, the delivery openings for the ground stock and the mill gas are housed by a stationary drop-delivery housing, in which the ground drops down, is delivered out below, and is transported to a downstream sifter, usually by a bucket elevator, whereas the mill gas, which is laden with finest grain, is drawn up out of the stationary product drop-delivery housing and likewise conducted to a sifter. The oversized material (grit) separated out by the sifter is re-circulated to the grinding stock input end of the tube mill. The tube mill and the at least one external sifter that has been necessary heretofore thus form a circulation milling system, whose construction, together with the necessary conveyor mechanisms such as bucket elevators and so on, requires relatively high outlay.